1. Field of the Invention
This invention relates to automotive manual transmissions, particularly to vibration damping in such transmissions.
2. Description of the Prior Art
German patent application DE-OS 36 34 174 describes a gear shift rod having a vibration damper. The rod consists of two tubular, mutually aligned shift rod portions, which transmit axial and rotary shifting motion produced by manual control of the vehicle operator on a gear selector lever. Resilient spring element located on a shift rod and rigid connecting elements, coaxial with and surrounding two shift rod portions, are provided. The shift rod assembly and vibration damper of this invention is costly to assemble and construct.
In the device described in the '174 patent application, a universal joint, connected by heavy dowel pins to a first shift rod portion, is fixed to a second shift rod portion. The two shift rod portions are surrounded by two tubular half shafts, held together by a tubular connecting element coaxially surrounding the two shift rod portions. Resilient spring elements in the form of O-rings also surround the shift rod portions.
This gear shift rod is able to damp pivoting movements between the two shift rod portions through radial deformation of the resilient spring elements, but axial and radial movements cannot be dampened by the heavy dowel pins because of the presence of a cordon-joint connection.